Owner's Manual

© January 2017 Takagi | Takagi.com
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TRGSS00116
Residential Gas
Tankless Water Heaters
SUGGESTED SPECIFICATIONS FOR TK-540P
The fully modulating, on-demand, condensing gas fired tankless water heater(s) with integrated recirculation pump shall be
Takagi Tankless Water Heater model TK-540P, having a maximum input rating of 199,000 Btu/h and available in NG or
LP. The heater shall have ¾ in. male NPT water and gas connections. The inlet gas supply pressures shall be 4.0 in. WC
(min.) up to 10.5 in. WC (max.) for NG and 8.0 in. WC (min.) up to 14 in. WC (max.) for LP. The indoor heater(s) shall
incorporate an integrated temperature controller that will provide pump control, diagnostic information, fault history, and heater
set temperature. The outdoor heater shall be factory supplied with a temperature remote, 100276687, that can be installed
up to 400 ft. from the heater using 20 gauge (minimum) control wire. The temperature remote shall provide pump control,
diagnostic information, fault history, and heater set temperature. The heater shall operate using 120 V / 60 Hz power source.
The indoor heater will incorporate a factory installed power cord.
The indoor heater shall be vented with 3” or 4” diameter schedule 40 PVC (solid core), CPVC, ABS, polypropylene or
category IV vent pipe with a length not to exceed 70 ft. (equivalent) for 3” vent or 100 ft. (equivalent) for 4” vent, terminating
horizontally or vertically. The intake pipe may use material such as PVC, (solid core) CPVC, ABS, aluminum, or Category IV
pipe and cannot exceed 70 ft. (equivalent) for 3” vent or 100 ft. (equivalent) for 4” vent. The indoor heater shall be able to
be common vented with schedule 40 PVC (solid core) pipe or approved polypropylene vent with a length not to exceed 100
ft. (equivalent) using up to 10 in. pipe. Proper sizing is provided in the heater’s installation manual. The outdoor heater(s) shall
be constructed with an integral exhaust vent on the front of the heater.
The water heater shall use a commercial grade copper alloy, fin tube primary heat exchanger with quick release brass
or bronze waterways. The secondary heat exchanger shall be constructed from stainless steel 316L. The heater shall be
controlled by an onboard solid-state printed circuit board which uses the following factory installed components: thermistors
to monitor inlet & outlet water temperature and exhaust temperature; a flow sensor to measure flow rate; a flame sensor to
monitor combustion; an air-fuel ratio rod to measure and adjust operation in order to maintain optimal combustion efficiency.
The heater also consists of inline fusing and surge absorbers for electrical surge protection, an electronic spark igniter,
aluminized stainless steel burners, hi-limit temperature switches to monitor water and exhaust temperatures, modulating gas
valve, an overheat cutoff fuse and ceramic heating blocks to protect the heat exchanger and water piping from freezing. The
indoor heater shall incorporate auto-fire system and a pump circulation operation for additional freeze protection. The indoor
model shall include an exhaust temperature monitoring system using an exhaust thermistor and automatic hi-limit switch to
maintain safe exhaust temperatures for sch. 40 PVC. The heater shall have a built-in condensate trap for the secondary
heat exchanger.
The heater can manifold into an Easy-Link to provide additional capacity. The Easy-Link controls shall be built onto the
onboard solid-state printed circuit board and does not require external controls. The linking control wire shall be supplied with
the heater.
The heater shall be design certified by CSA according to ANSI Z21.10.3 • CSA 4.3, approved for sale in the United
States, ENERGY STAR
®
qualified, has a minimum energy factor of 0.95, meets the energy efficiency requirements of the U. S.
Department of Energy and ASHRAE 90.1 and complies with SCAQMD Rule 1146.2 and other air quality districts with similar
requirements for low NOx emissions of 14 ng/J or 20 ppm.